4 – Anyone who intends to leave a bequest should hasten to put it into effect himself. By doing so he secures the entire reward, and he can distribute it exactly as he wishes in terms of amount, type, and avenue of disbursement.
5 – The heirs should likewise rush to carry out the deceased’s bequests so that they may earn the reward for doing so. More important still is to hasten in fulfilling the obligatory duties and liabilities that rested upon the deceased—whether they are Allah’s rights, such as pilgrimage, zakah, expiations, and vows, or people’s rights, such as debts.
6 – The living should take the initiative in performing acts of obedience and good works. This worldly life is a race to acquire virtues and seize reward; the higher a person rises in virtuous deeds, the loftier his rank will be in the Abode of Recompense.
Scholarly disagreement
The scholars agree, as a matter of established knowledge, that the reward of supplication, seeking forgiveness, and financial acts of worship—such as charity, pilgrimage, and ʿumrah—reaches the deceased.
The proof for supplication and seeking forgiveness is the verse: “And those who came after them say, ‘Our Lord, forgive us and our brethren who preceded us in faith’” (Quran 59:10), and the Prophet’s ﷺ instruction: “Ask forgiveness for your brother, for he is now being questioned” (reported by Abū Dāwūd).
The evidence for charity is the hadith under discussion.
As for pilgrimage, al-Bukhārī relates that a woman from Juhaynah said, “Messenger of Allah, my mother had vowed to perform Hajj but did not do so before she died. May I perform Hajj on her behalf?” He replied, “Yes—perform Hajj for her. Fulfill your obligation to Allah, for Allah is most deserving of fulfillment.”
The hadiths and reports on this subject are extremely numerous. Ibn al-Qayyim gathered a good selection of them in Kitāb al-Rūḥ.
Shaykh al-Islām said: “The leading scholars of Islam unanimously agree that the deceased benefits from the living’s supplication for him and from righteous deeds performed on his behalf. This is something known necessarily in the religion of Islam, supported by the Quran, the Sunnah, and consensus; whoever rejects it is counted among the people of innovation.”